Refactor: use new functions in stdlib code

js/js.libraries/src/core/collections/InternalHashCodeMap.kt

@@ -153,8 +153,8 @@ internal class InternalHashCodeMap<K, V>(override val equality: EqualityComparat
     }
 
     private fun getChainOrNull(hashCode: Int): Array<MutableEntry<K, V>>? {
-        val chain = backingMap[hashCode]
-        return if (chain !== undefined) chain else null  // satisfying { it != undefined }
+        val chain = backingMap[hashCode].unsafeCast<Array<MutableEntry<K, V>>?>()
+        return chain.takeIf { it !== undefined }
     }
 
 }

js/js.libraries/src/core/collections/LinkedHashMap.kt

@@ -64,8 +64,7 @@ public open class LinkedHashMap<K, V> : HashMap<K, V>, Map<K, V> {
 
                 val current = next!!
                 last = current
-                next = current.next
-                if (next === head) next = null // satisfying { it != head }
+                next = current.next.takeIf { it !== head }
                 return current
             }
 

libraries/stdlib/src/kotlin/concurrent/Thread.kt

@@ -44,5 +44,5 @@ public fun thread(start: Boolean = true, isDaemon: Boolean = false, contextClass
  */
 @kotlin.internal.InlineOnly
 public inline fun <T: Any> ThreadLocal<T>.getOrSet(default: () -> T): T {
-    return get() ?: default().apply { set(this) }
+    return get() ?: default().also(this::set)
 }